N8 ... at 17" high I think a fan would be overkill. From what I remember from college chemistry the behavior of the water vapor will obey the gas laws, and that after a time, say, a few hours or whatever, the gas in your system (humidor) will be completely disordered, with the water molecules bouncing around in every direction equally (entropy). The drawers themselves won't stop tiny gas molecules. There may be some temperature differential from top to bottom (heat rises), but at 17" it would be so small as to be negligable. Probably just using the right volume humidifier (humicare beads highly recommended however) to humidor volume will do the trick.
